/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.tuscany.sca.extension.helper.impl;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.xml.namespace.QName;

import org.apache.tuscany.sca.assembly.AssemblyFactory;
import org.apache.tuscany.sca.assembly.Binding;
import org.apache.tuscany.sca.assembly.xml.Constants;
import org.apache.tuscany.sca.contribution.ModelFactoryExtensionPoint;
import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessor;
import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessorExtensionPoint;
import org.apache.tuscany.sca.core.ExtensionPointRegistry;
import org.apache.tuscany.sca.core.ModuleActivator;
import org.apache.tuscany.sca.extension.helper.BindingActivator;
import org.apache.tuscany.sca.extension.helper.ComponentLifecycle;
import org.apache.tuscany.sca.extension.helper.InvokerFactory;
import org.apache.tuscany.sca.interfacedef.InterfaceContract;
import org.apache.tuscany.sca.interfacedef.Operation;
import org.apache.tuscany.sca.invocation.Invoker;
import org.apache.tuscany.sca.invocation.Message;
import org.apache.tuscany.sca.provider.BindingProviderFactory;
import org.apache.tuscany.sca.provider.ProviderFactory;
import org.apache.tuscany.sca.provider.ProviderFactoryExtensionPoint;
import org.apache.tuscany.sca.provider.ReferenceBindingProvider;
import org.apache.tuscany.sca.provider.ServiceBindingProvider;
import org.apache.tuscany.sca.runtime.RuntimeComponent;
import org.apache.tuscany.sca.runtime.RuntimeComponentReference;
import org.apache.tuscany.sca.runtime.RuntimeComponentService;

/**
 *
 * @version $Rev$ $Date$
 */
public class BindingsActivator implements ModuleActivator {

    protected List<BindingActivator> bindingActivators;
    protected AssemblyFactory assemblyFactory;
    protected Map<Class, BindingActivator> bindingActivatorMap = new HashMap<Class, BindingActivator>();

    public void start(ExtensionPointRegistry registry) {

        ModelFactoryExtensionPoint factories = registry.getExtensionPoint(ModelFactoryExtensionPoint.class);
        this.assemblyFactory = factories.getFactory(AssemblyFactory.class);


        this.bindingActivators =
            DiscoveryUtils.discoverActivators(BindingActivator.class, registry);

        StAXArtifactProcessorExtensionPoint staxProcessors =
            registry.getExtensionPoint(StAXArtifactProcessorExtensionPoint.class);

        ProviderFactoryExtensionPoint providerFactories =
            registry.getExtensionPoint(ProviderFactoryExtensionPoint.class);

        for (final BindingActivator bindingActivator : bindingActivators) {
            Class bindingClass = bindingActivator.getBindingClass();
            bindingActivatorMap.put(bindingClass, bindingActivator);
            QName scdlQName = getBindingQName(bindingClass);
            staxProcessors.addArtifactProcessor(new BindingSCDLProcessor(scdlQName, bindingClass));

            // Check if the binding extends from Binding interface
            if (Binding.class.isAssignableFrom(bindingClass)) {
                // Add provider factory against the binding class
                providerFactories.addProviderFactory(new DelegatingBindingProviderFactory(bindingClass));
            }

        }

        // Add a generic provider factory against PojoBinding.class
        providerFactories.addProviderFactory(new DelegatingBindingProviderFactory(PojoBinding.class));
    }

    public void stop(ExtensionPointRegistry registry) {
        StAXArtifactProcessorExtensionPoint staxProcessors =
            registry.getExtensionPoint(StAXArtifactProcessorExtensionPoint.class);
        ProviderFactoryExtensionPoint providerFactories =
            registry.getExtensionPoint(ProviderFactoryExtensionPoint.class);

        for (final BindingActivator bindingActivator : bindingActivators) {

            // Remove the binding SCDL processor from the runtime
            if (staxProcessors != null) {
                StAXArtifactProcessor processor =
                    staxProcessors.getProcessor(getBindingQName(bindingActivator.getBindingClass()));
                if (processor != null) {
                    staxProcessors.removeArtifactProcessor(processor);
                }
            }

            // Remove the ProviderFactory from the runtime
            if (providerFactories != null && bindingActivator.getBindingClass() != null) {
                ProviderFactory factory = providerFactories.getProviderFactory(bindingActivator.getBindingClass());
                if (factory != null) {
                    providerFactories.removeProviderFactory(factory);
                }
            }
        }
        if (providerFactories != null) {
            ProviderFactory factory = providerFactories.getProviderFactory(PojoBinding.class);
            if (factory != null) {
                providerFactories.removeProviderFactory(factory);
            }
        }
    }

    protected QName getBindingQName(Class bindingClass) {
        String localName = bindingClass.getName();
        if (localName.lastIndexOf('.') > -1) {
            localName = localName.substring(localName.lastIndexOf('.') + 1);
        }
        if (localName.endsWith("Binding")) {
            localName = localName.substring(0, localName.length() - 7);
        }
        StringBuilder sb = new StringBuilder(localName);
        for (int i = 0; i < sb.length(); i++) {
            if (Character.isUpperCase(sb.charAt(i))) {
                sb.setCharAt(i, Character.toLowerCase(sb.charAt(i)));
            } else {
                break;
            }
        }
        return new QName(Constants.SCA10_TUSCANY_NS, "binding." + sb.toString());
    }

    private final class DelegatingBindingProviderFactory implements BindingProviderFactory {
        private Class modelType;

        public DelegatingBindingProviderFactory(Class modelType) {
            super();
            this.modelType = modelType;
        }

        public ReferenceBindingProvider createReferenceBindingProvider(final RuntimeComponent rc,
                                                                       final RuntimeComponentReference rcr,
                                                                       final Binding b) {
            final Object realBinding;
            if (b instanceof PojoBinding) {
                realBinding = ((PojoBinding)b).getUserBinding();
            } else {
                realBinding = b;
            }
            final BindingActivator bindingActivator = bindingActivatorMap.get(realBinding.getClass());
            return new ReferenceBindingProvider() {
                List<InvokerProxy> invokers = new ArrayList<InvokerProxy>();
                private InvokerFactory factory;

                public Invoker createInvoker(Operation operation) {
                    InvokerProxy invoker = new InvokerProxy(factory, operation);
                    invokers.add(invoker);
                    return invoker;
                }
                
                public boolean supportsOneWayInvocation() {
                    return false;
                }

                public InterfaceContract getBindingInterfaceContract() {
                    return null;
                }

                public void start() {
                    if (b instanceof PojoBinding) {
                        factory = bindingActivator.createInvokerFactory(rc, rcr, b, ((PojoBinding)b).getUserBinding());
                    } else {
                        factory = bindingActivator.createInvokerFactory(rc, rcr, b, b);
                    }
                    if ( (factory != null) &&  (factory instanceof ComponentLifecycle)) {
                        ((ComponentLifecycle)factory).start();
                    }
//                    for (InvokerProxy invoker : invokers) {
//                        invoker.start(factory);
//                    }
                }

                public void stop() {
                    if (factory instanceof ComponentLifecycle) {
                        ((ComponentLifecycle)factory).stop();
                    }
                }
            };
        }

        public ServiceBindingProvider createServiceBindingProvider(final RuntimeComponent rc,
                                                                   final RuntimeComponentService rcs,
                                                                   final Binding b) {
            final Object realBinding;
            if (b instanceof PojoBinding) {
                realBinding = ((PojoBinding)b).getUserBinding();
            } else {
                realBinding = b;
            }
            final BindingActivator bindingActivator = bindingActivatorMap.get(realBinding.getClass());
            return new ServiceBindingProvider() {
                ComponentLifecycle listener = bindingActivator.createService(rc, rcs, b, realBinding);

                public InterfaceContract getBindingInterfaceContract() {
                    return null;
                }
                
                public boolean supportsOneWayInvocation() {
                    return false;
                }

                public void start() {
                    listener.start();
                }

                public void stop() {
                    listener.stop();
                }
            };
        }

        public Class getModelType() {
            return modelType;
        }
    }

}

class InvokerProxy implements Invoker {
    InvokerFactory factory;
    Invoker invoker;
    Operation op;

    InvokerProxy(InvokerFactory factory, Operation op) {
        this.factory = factory;
        this.op = op;
        this.invoker = factory.createInvoker(op);
    }

    public Message invoke(Message arg0) {
        return invoker.invoke(arg0);
    }

//    public void start(InvokerFactory factory) {
//        invoker = factory.createInvoker(op);
//    }
}